The Conquering Demon Lord of a Devilish New World
by Trick N. Zwei
Summary: Oga Tatsumi, along with his friends, are accidentally sent to a different dimension due to baby Beel's father. The Child Rearing Badass is now being encouraged by Hilda to conquer this new world in the name of Beelzebub via domination of the Ranking Games. With his friends as his peerage, they are now set on a collision course with the powers that be in this brand new playground.


**Disclaimer: I make no claims of owning Beelzebub or Highschool DXD, only the OC that appear in this fanfic. Don't sue me, I'm really poor.**

 **This is just a oneshot! Therefore, there may be more than a few inconsistencies with canon, since I'm only really familiar with one of the series.** **It is also pretty bare-bones with only about 3k words so it probably has some problems.**

 **Hope you enjoy it, as short as it is.**

* * *

Once upon a time, there was once a very handsome, very kind, very cool, popular, smart, talented, and incredibly strong young man named Oga Tatsumi. He and his many, not as good as he was, friends lived in a world where every day was lively and eventful.

It was in one of those usual days of happiness and peace that something unexpected occurred.

The father of the baby that he well cared for had come to pay him a visit.

"Yo! How's everyone doing today?!" casually greeted the Great Demon Lord Beelzebub III.

Oga and his friends, who were busy playing together happily in front of the open space of Ishiyama High, froze in place. It was, after all, very strange to see the most powerful man of the Demon Kingdom visit a regular, peaceful, and _absolutely_ normal high school… really, it is.

"Oi… Oga, isn't that baby Beel's old man?" said one of his minio- uh… I mean friends, Kanzaki Something. "And let go of my neck already! I think I'm about to pass out!"

"Mufuufhu mur phut," said another of his good friends, Himekawa Pompadour.

"What's he saying?" Oga asked Toujou, who was in front of him holding his shirt to kindly get some dirt off of it.

"Beats me."

"I said to get your damn foot off my face!" Himekawa answered loudly as his nose bled after being in the sun too long. "Also, why the hell would the Great Demon Lord come visit here?"

"Somehow, I've got a really bad feeling about this," said Creepichi uneasily, who had come out from hiding underneath some of the other students.

They were surrounded by the many other Ishiyama High students who came to play as well. Unfortunately, a lot of them weren't as energetic as Oga and his friends so they were all quietly and peacefully sleeping on the ground and laying all over each other, not noticing the presence of the demon. They had played so hard that they barely noticed themselves getting a few little scratches and bruises here and there, along with a little of their blood splattering the ground.

"I can see you're still doing well in teaching my little kid how to easily crush humans. Damn, this is like a scene from hell," the Demon Lord said, probably mistaking the nature of games they were playing for some reason. "Good work, Good work!" he clapped.

"Daaaa! Daaaa!" shouted the innocent baby boy strapped to Oga's back toward his no good lazy ass bastard of a father, who couldn't be counted on to raise his own kid because he was too busy playing around, and pretty much dumped him on a poor, but fortunately, saintly young man as his permanent babysitter.

"My lord, you're here!" Hilda came down from the tree she was perched on and watching the massac-… massive fun the students were having. "I offer you my humblest apology for not preparing for your arrival!" she said as she knelt before the good-for-nothing rotten bastard.

"It's fine, it's fine," waived off the Great Demon Lord. "I just came on a whim since I just got my hands on a new toy for my son." He laughed as he reached for a small intricately decorated black box in from his coat pocket.

"What the heck is that?" asked Oga curiously.

The group of friends decided to postpone their bloody brawl and check out the mysterious toy that the Demon Lord had brought.

"What is it?" said Toujou. "Is it that Reddit cube?"

"Hah?" Himekawa shook his head. "I think you mean Rubik's cube."

"Right," nodded Toujou. "Schrodinger's box."

"Wrong! And how the hell did you mistake it with a more complicated word?!"

The Demon Lord decided to explain things to everyone before people got dumber. "This is a rare trans-dimensional window box that was discontinued a few centuries ago," he said. "I actually found one somewhere in my closet yesterday and modified it a little bit so that my little boy can use it anytime to talk with us back in the demon world. It's a lot easier than travelling using a transdimensional demon."

"Hooh?!" Everyone seemed genuinely impressed by this.

"Isn't that great, young master?" said Hilda with a happy smile. "We can talk with Madam Iris everyday now. Why don't you go ahead and give it a try?"

The Demon Lord placed the small black cube on the ground. Baby Beel was pretty curious about the device that his father brought and wasted no time in crawling down Oga to inspect it.

"Such a useful thing, I wonder why they stopped making it?" asked Furuichi.

"Oh, that," said the Demon Lord. "Actually, they had to recall all of it because it wasn't working right. I think it was due to dimensional interference or something that made the connection pretty useless. You don't have to worry about that though since I made it work by changing a few things and supercharging it myself so you can continuously use it."

"…You… changed a few things in it?" Furuichi said as Baby Beel shook the black cube up and down. "Are you sure that it's safe to use?"

"Well there was a warning about it being capable of opening a dimensional portal, but the manual did say that it was impossible to happen since it would need a super massive amount of energy that the device couldn't possibly have."

Furuichi and Hilda, the only two who were listening to the Demon Lord, both blanched at this. "But… didn't you just say that you supercharged it?" he said as baby Beel now began smacking the device on the ground with Oga and his friends who were giving helpful comments on how to break open the device to make it work.

The Demon Lord stopped moving for a few moments. "Ah…. Yeah, that would be bad…"

At that time, baby Beel had found a rock that he used to violently beat into the black cube.

"Master, don't!" shouted Hilda.

"Stop him, you idiots!" Furuichi screamed in a girlish cry. "Don't encourage him!"

The box suddenly glowed ominously red. A dark swirling black and reddish portal opened up from it and quickly tried to suck in baby Beel.

Fortunately, the manly Oga was there to grab hold of him.

"Like hell, I'm going to let a toy mess with us again!" he said.

It was also quite fortunate that he had so many dependable friends to rely on when he needed them.

"Damn you, Oga!" shouted Kanzaki. "Let go of my leg, you idiot! I don't want to die because of you!" It was great that he was so close by to lend Oga a hand-er… leg, whatever, to hold on to so he didn't get sucked into that thing.

"I should say the same thing to you, you fucking moron!" Himekawa said. "I was almost in the clear, shit!" He was kind enough to be the anchor holding the guys to a tree. "Where the hell is Toujou?! Help us out here, you damned meathead!"

Suddenly, Toujou stood in front of Himekawa, just outside the vortex's pull. "Don't worry you guys," he said as he cracked his knuckles. "I know how to fix this." The confidence in his face and words had seemed so reliable. "All I have to do is find that kitty cat and the puzzle is solved!"

Everyone looked dumfounded as they saw the idiot roar out and charge into the raging black hole behind them…

…He disappeared without a trace into the black nothingness.

" _That dumbass!"_ thought everyone.

"Tsk!" Himekawa's grip was slipping on the tree as the vortex got stronger. "Damn it all!" he shouted as his grip failed. But to his surprise, someone grabbed him. "Aaahh! That fucking hurts dammit!" he yelled as someone held tightly onto his pompadour.

"Gaaaaahh! What did I do to deserve this?!" Furuichi cried like a little bitch as he grabbed on hold.

"Shut up! I'll kill you if you let go!" said Hilda, who was holding onto Furuichi's leg as the handle of her umbrella was anchored to the tree.

The tree started to break though, and soon, left nothing for the umbrella to hold on to. Everyone said their final words as they approached the blackened sphere that consumed everything.

"At least I'll die with you, young Master!"

"At least I'll die being held by a woman!"

"This is a stupid way to die!"

"I didn't get to eat my special edition Yogurtchi!"

"I swear I'll fucking kill you, you stupid retarded Demon Lord!"

"Dah!"

Silence followed, as they were swallowed in by the black sphere.

On that day, the entire world cried as they lost one of the most cherished and important person ever to live. Oga Tatsumi was celebrated as a Hero, with great works of arts and music dedicated to him as the people grieved for the loss of such a man that will never walk the earth ever again. How great was their sorrow indeed.

The End.

…

…

…

…

"AS IF!"

Furuichi, Hilda, Himekawa and Kanzaki all smacked down Oga's head hard and deep into the monumental length stone table he was sitting in front of.

"To hell with your narration!" shouted Furuichi angrily as he grinded the head more into the table. "Where the hell do you get off introducing me to a new world as Creepichi!"

"How dare you insult the Demon Lord so many times," said Hilda, though she didn't really deny any of it. She also helped in grinding down on the head more. "And what's with calling yourself smart, cool, and all those other lies, you fool. Do you think you're some sort of God given hero? Are you Superman? What a joke!"

"What's with those names you gave us as well, huh? You've known us for more than a year already!" Kanzaki said as his face was dark with anger. "And didn't you just referred to us as your minions there, right?!"

"Friends my ass," said Himekawa darkly as he pressed down hard on Oga's hard head. "I wouldn't be in this mess if it weren't for you! I'll seriously grind your head till your brain leaks out!"

"You didn't even mention us at all," whined Hanazawa with a pout, who was drinking tea casually with Kunieda and the other Red Tail girls on the table. "Don't hog all the spotlight."

"What about us too?" Natsume smiled awkwardly and pointed to himself along with Shiroyama. "It really feels like we're just background characters here." –true.

The majestic and rather large room where they were all in seemed a bit crowded due to the number of people currently occupying the place. It was a space that was designated for them to debrief their current hosts who were kind enough to shelter them for the time being.

"Now, now," said their host, Sirzechs Lucifer, trying to calm all the madness down. "Let's all just relax and someone else can clarify and explain the other missing details." His brilliant red hair was a bit disheveled after trying to get the full story straight for the 4th time.

He, his maid, and two other companions were welcoming the sudden arrivals of visitors from another dimension. Unfortunately, like most first contacts in history, it wasn't a very peaceful first meeting.

"More specifically, can you tell us why you suddenly attacked one of our patrols?" he asked politely. "Their reports said that they merely wanted to ask you a few questions, and that they made no provocation of any sort that would warrant such a response."

The Ishiyama High student's eyes all looked accusingly towards the one responsible for that specific matter.

Toujou sweated a little and looked down on his tea, suddenly quite interested in how they made it. "I-I didn't know how to answer their questions… so I chose one of the few choices I had at the time." He was the first one into the dimensional portal so it was natural that he had been the first one to meet the devils.

His choices consisted of: a) Kill b) Threaten c) Punch d) Kill e) Beat up f) Kill g) Talk.

…Actually, what happened seemed quite fortunate, when you consider those options. By the time Oga and the rest had arrived, they already saw Toujo sitting on a pile of bodies.

"So you pummeled them half-dead because you didn't know how else to respond?" gaped the Satan, Lucifer, in disbelief.

Contrary to him, his comrade was much more positive about it. "Ahahhahahah!" she laughed out loudly. "That's a pretty bad reaction. You guys sure are weird!"

The Ishiyama High students looked deadpan at the one who said that. It was understandable, considering the one who said it was dressed up as a magical girl and had introduced herself as the Ultimate Female Devil Levia-tan~!

Sirzechs groaned to himself as he pretty much understood their reaction. "Could you not have dressed normally, Sera?" he asked. "You're not making us a good impression to our visitors from another world, and you're supposed to be in charge of foreign affairs."

"Hmm?" wondered Serafall Leviathan. "But these are my normal clothes."

Yeah, the impression the foreigners got were pretty much burned in already after that.

"Let's try and get back on track here," said Ajuka Beelzebub. He was quite interested in their guest's world and circumstances. "How about you start explaining to us how the rest of your people manage to arrive here as well? That part wasn't included in what had been told to us just now."

"About that…"

Kunieda Aoi would be the one to explain what happened after.

* * *

"…This is bad…"

The Demon Lord was standing at a distance away from the black sphere that had just eaten his son and contractor, along with their servants. He had his hands pressed down on his head as he thought of how majorly he had just messed up.

"Iris will kill me for this…" he muttered as he chewed nervously on his thumb. "And we just made up a little while ago too. I've got to get them back somehow… but how? I can't get close to that thing without it sucking me in too."

"Oi! Kanzaki!" shouted someone coming out of the school building. "We brought your special Yogurtchi! Let's all ta- w-what on earth happened here!" Natsume and Shiroyama gaped at the massive black hole where they last saw Oga and the rest were fighting.

"Kanzaki! Where'd he go?!" Shiroyama asked worriedly.

"Hehehe…" The Demon Lord jumped over behind the two and grasped their shoulders tightly. "Solution… GET!"

"W-what? Who the heck is this weirdo?!" said Shiroyama.

Natsume paled immensely as he saw who it was. "Aren't you… the Great Demon Lord?"

"Bingo!" smiled the Demon Lord. "Now if you want your friends back, I'm going to need your help. So I want you to do exactly as I say."

Natsume and Shiroyama had an uneasy feeling about that but had little choice in the matter since they couldn't really oppose the Great Demon Lord.

A minute or two later, the Red Tails led by Kunieda happened upon an unexpected scene in front of their school. It wasn't the black vortex that swirled dangerously that caught their attention. No, it was the image of the Great Demon Lord using Natsume and Shiroyama like a Barrel of Monkeys to fish something out of the sphere that had really stumped the girls.

"Perfect timing!" shouted the Demon Lord as he spotted the girls. "I need to extend this a bit more." He used his demonic powers and pulled the girls over to him.

"Kyaah!"

"What the hell?!"

"Aoi-neesan grab my hand!"

"Hahahahah!" the Demon Lord laughed proudly as he was holding onto Kunieda Aoi's hands now. "With this, I can fish out my boy!" The girls were quite confused and unaware of just what the hell was going on here. "There's no need to worry. I, the Great Demon Lord, shall never let go in the face of—Achooo!" He sneezed loudly after a leaf fell down the tree and tickled his nose.

"Waaaah!" the girls and boys screamed as they got sucked into the vortex.

The blackened sphere pulsed for a moment and then dispersed into nothing, leaving only the Great Demon Lord and the unconscious students alone in Ishiyama High.

"Definitely… not good."

* * *

"That is…"

"Sounds really…"

"Dumb… that guy is completely dumb!" finished the only female of the four Satans bluntly. "Seriously, you're saying that guy is the ruler of Hell there?" None of the students could look them in the eye or admit it at all. Even Hilda sat quietly in the corner, trying hard to be ignored. The shame was too much to bear, especially with a magical girl doing the criticizing. "I really feel sorry for you guys."

The only one who was able to say anything at all was the baby on Oga's buried head.

"Dah! Dah! Mah! Dah!" he began spouting while pointing angrily towards Serafall. It looked like he wasn't pleased with someone insulting his dad.

Sirzechs and Ajuka were stunned, unable to respond to that at all.

"My! What a cute little baby!" Serafall was the only one among the Satans with a different reaction. "Here, let me hold you a little bit." She quickly came over and picked baby Beel up from Oga's buried head. "Oh, you're such a cutie! Yes, you are!" she said as she pampered the kid.

 _"Why is he naked?"_ thought Sirzechs and Ajuka.

Sirzechs decided to ignore his fellow Satan and continued, "So do you guys have any plans on how to get back?"

"I'm sure the Demon Lord is currently doing all he can to find a way to do so," Hilda said confidently. "We will just need a place to stay until that time."

"Hmmm…" wondered Sirzechs. "Well, I suppose I could put you in the school our family runs with the Sitri clan. That way you can continue your education while waiting for your return home."

"A school run by devils?" said Furuichi uneasily. "I feel like something will definitely go wrong with that setup."

"Yeah," laughed Sirzechs. "I feel like it would have been nice to have more guys there though, since that place only became co-ed recently and the girls still outnumber the guys by quite a bit."

In the blink of an eye, Furuichi was on his knees and holding Sirzech's hands in his. "Please! Allow us the honor of attending such a wonderful school from another world!" The Satans were amazed by his speed and seriousness, but the Ishiyama high students looked only with disgust. "It would be a shame if we weren't able to learn anything new about this place, after all. Let us not waste such a valuable opportunity of checking out the women of this world!"

There was no shame at all in that last sentence of his.

Still, since no one else had any other options besides that, there were no disagreements from the surrounding students to the plan. They just thought it would be just like their time at St. Ishiyama so they weren't at all bothered by it.

Thus, this was how the delinquents have arrived to take Kuoh Academy by storm. And how demons came into contact with the devils, angles, and all other sorts.

* * *

 **A/N:**

 **This is a lot rougher than the other oneshot since this one has a high chance of actually getting made. I would just rewrite a lot of it when that does happens so I didn't go through this as much as "A Monster's Innocence."**

 **I've already got the Evil Pieces ready for Oga and his gang so the only other thing needed here is for me to actually pick a part of Highschool DXD's history to throw them in. I'm not putting them at the very beginning that is for sure. I'll have to either read the source material or go with the anime adaptation. I have not seen any of the those so the Satans may be OOC since I only remember them from a few of the crossfics I read here.**

 **If this does happen, it won't be in a while, since I'm still focusing on my main crossfic for now.**

 **Next up, Korra x FMA oneshot!**


End file.
